In Elorus, you can create your own series of sales documents and estimates by selecting Settings -> Numbering sequences -> Add.
Every series can be designated to one document type. When you add a new series on the application, you also define the document type to which it applies.
If you wish to add a series to more document types, all you need to do is ‘Add’ the series for each one of those types.
To apply a numbering series in your documents, you need to select it from the Number field.
Suppose that you created series “A” for both the “Invoice” and “Credit Invoice” document types. The first “Invoice” that you create will receive the numbering #A-1, the next one will receive numbering #A-2 et c. The first "Credit Invoice" will again receive #A-1 , #A-2 without affecting "Invoice" numbering sequence. This helps prevent gaps in numbering without the necessity of multiple names for each series.